In many communications systems, the transmission of a data packet from a source node to a destination mode may require an acknowledgement packet (“ack packet”) to be sent by the destination node to the source node to provide the latter notification of the successful receipt and validation of the data packet. In this way, the source node receives feedback regarding the transmission of the data packet. The requirement of responsive ack packets may be needed in some communications system in order to implement a packet retransmission scheme in order to meet a quality of service (QoS) requirement of upper layer applications.
In prior communications systems, after a source node transmits the data packet, the source node scans the channel only once for the ack packet from the destination node. If it does not receive the ack packet, the source node will then schedule a retransmission of the data packet to the destination node or mark the data packet as a failed transmission, depending on if the number of maximal allowed retransmissions has been met or not. In such systems, the retransmission rate or the number of failed transmissions may be very high depending on the channel conditions, which would most likely adverse affect the QoS of the communications session between the source and destination nodes.